Stock price when the opinion was issued
3X leverage gives you the same level of volatility as stocks, but in the bond market. Keep in mind this is a very risky investment, as the bond markets are going through so much turmoil. Keep your investment small, not 10-20% of your portfolio. Start with 3-4% and build. A bet on inflation declining. His view is that inflation in NA will be around "2.something"% next year.
He has a personal position but not a client one. It follows the bond price movement. Interest rates are expected to go down and therefore bond prices to go up. Bonds can't go bankrupt but their upside is limited. They are tied to interest rates and can be used as a hedge.
Triple leverage. You can actually lose money, because it resets every day to give you the 3 to 1. Rates are going down at the front end, but the back end's worried about inflation. If that's the case, the long end's going up and this is not the vehicle for you.
He never recommends the leveraged ETFs to any but the shortest timeframe traders looking for leverage over a couple of days or a week or two, at most. You don't want to hold these things long term at all, ever.